Mellow Yellow is Happy Hippo's rarest Yellow Vein Kratom. Yellow Sundanese is a super Unique Kratom Leaf that helps put Yellow Vein on the map. We truly believe this Leaf will be of interest to You! Particularly, for any Hippo that is striving to become a more Mellow Human being. Life can make Humans uptight, uncomfortable, sometimes even sad. Let Puddles tell you why he is so Confident in Mellow Yellow Hippo — especially those ...